To producing an olefin having a desired chain length, commonly known is a method of oligomerizing a short-chain olefin such as ethylene to synthesize an α olefin. The method of oligomerization unfortunately fails to produce only an olefin having a desired chain length at high yield due to distribution in the degree of polymerization.
There are also known methods for producing an olefin from a carboxylic acid, including a method of production from a carboxylic acid in the presence of a Pd complex catalyst (U.S. Pat. No. 3,530,198), a method of production of an α olefin from a carboxylic acid in the presence of an acid anhydride and a catalyst containing an element selected from Group 8, Group 9, and Group 10 metals and copper (U.S. Pat. No. 5,077,447), and a method of production of an α olefin from a carboxylic acid in the presence of a Pd complex catalyst and a pivalic anhydride (Chem. Commun., 724, (2004)). These methods have employed a special additive or a particularly high reaction temperature of not less than 250° C. to enhance olefin production efficiency, but unfortunately resulting in an unsatisfactory yield of a desired olefin.
Recently, the present inventors have found that use of a catalyst containing an iodine element and at least one metal element selected from Groups 6 to 11, or a combination of an iodide and a catalyst containing a metal element selected from Group 8, Group 9, and Group 10 and copper could produce an olefin at high yield under relatively mild conditions, and disclosed in JP-A2010-168340, which corresponds to WO-A2010/024420.